Vehicles are provided with a water pump which circulates cooling water and an oil pump which circulates oil. The water pump can be divided into an engine powered water pump which operates by receiving power from an engine through a belt connected to an engine rotary shaft, and an electrical water pump which operates by a battery. Since the electric water pump does not require power from the engine, it improves fuel efficiency and precisely controls the temperature of cooling water.
In a typical motor, a stator assembly is fixed to a housing. The stator assembly is press-fitted into the housing after expanding the housing by high-frequency heating for time saving purpose.
Although this hot-fitting method is simple to operate and can obtain strong fastening force, this method is not applicable for a sliding structure assembly.
Korean Laid-Open Patent Publication No. 10-2003-0066157 A, titled “STRUCTURE FOR FIXING INNER STATOR OF COOLER,” was made in order to overcome the problem of the related art. This publication relates to the structure for fixing an inner stator of a cooler which is bonded and fixed to the outer circumference of a cylinder. Specifically, male threads are formed on one end of the cylinder, and a hollow disk-shaped fixing ring having female threads spirally engages into the cylinder having the male threads so that the inner stator is fixed to the outer circumference of the cylinder.
However, the structure and process are complicated, abrasion occurs, and there are gaps causing vibration and noises.
Accordingly, a canned motor pump that has a simple structure and process, removes vibration and noise, and has superior endurance is required.
The foregoing is intended merely to aid in the understanding of the background of the present disclosure, and is not intended to mean that the present disclosure falls within the purview of the related art that is already known to those skilled in the art.